I'm not sure I followed all that (did you miss out steps on wiping old drives before installing in 424?).
However, consider using Traid instead of Raid 5 (step 2) as I think this format is easier to add/expand than raid 5.
Yes, use your disk A as initial backup. Install/format 2 drives as Traid then copy off A. Add A to Traid - this will give you 8TB in effectively Raid5.
Copy across rest of your data.
{NB Raid 5 on 2 drives is not really a 'thing' - Traid on 2 drives IS a Raid1 mirror. Traid on 1 drive is possible with an add/expand later.
Drive array types are not necessarily interchangeable across devices. TNAS may do things differently to your other devices.
Just my 2p worth.
However, consider using Traid instead of Raid 5 (step 2) as I think this format is easier to add/expand than raid 5.
Yes, use your disk A as initial backup. Install/format 2 drives as Traid then copy off A. Add A to Traid - this will give you 8TB in effectively Raid5.
Copy across rest of your data.
{NB Raid 5 on 2 drives is not really a 'thing' - Traid on 2 drives IS a Raid1 mirror. Traid on 1 drive is possible with an add/expand later.
Drive array types are not necessarily interchangeable across devices. TNAS may do things differently to your other devices.
Just my 2p worth.
Statistics: Posted by Gremlin — Yesterday, 19:18